I anticipate I'll have the same problem, but with my own parents so it's something I have to be the one to set boundaries but it's hard. When I was first Tri pregnant my husband had to stay out for work for 2 weeks, and my parents just barge in almost everyday to cook, nag, rearrange the things in the house, even though I keep telling them not to. They don't even live nearby but have a car. It pisses me off but I can't be hostile at them either because I know they meant well, so it eats me up inside. It must be a lot more annoying now that you are recovering and also have a LO.
You can ask your husband to speak to the easier going of the in laws to sound out that they are stressing you out and hampering your family bonding time and recovery and to stay away. One sneaky way is to tell them to give a heads up before coming over so you can even come up with an excuse to avoid them, like you have a doc appointment, another friend over, going out to the park etc.
Older folks are hard headed though, if all persuasions fail, for me I'll opt to preserve the peace with the in laws instead of being hostile. There are a lot of things that are just bopian in life, looking to the future you know your LO will have a large family support, grandparents who care in their own way, and you still have many many years to bond with your kid as he grows through puberty. In the olden days the whole family helps out with child rearing, the kids are still close to their parents despite all the aunts and uncles and cousins never putting the baby down. It may be vexing, but be assured that your bond won't be damaged.